Consanguinidad Help

My 3rd great grandparents were Eulogio Alvarez Flores and Carmen Flores Gonzalez. In the marriage info it says that they are related by "el parentesco de segundo con tercero de consanguinidad" Eulogio's parents were Jacinto Alvarez and Vicenta Flores. Carmen's parents were Carmen Flores and Antonia Gonzalez. I would like to know how they were related.

Rafael Meraz